Creating delicious Pumpkin-Oatmeal Muffins is straightforward. Just follow these simple steps:

1. Preheat Oven: Set your oven to 350°F (175°C) and line a muffin tin with paper liners or grease it lightly.
2. Mix Wet Ingredients: In a large mixing bowl, combine the pumpkin puree, brown sugar, granulated sugar, vegetable oil, eggs, and vanilla extract. Whisk until smooth.
3. Add Oats: Stir in the rolled oats, allowing them to soak in the wet mixture for a few minutes.
4. Combine Dry Ingredients: In another bowl, whisk together the flour, baking powder, baking soda, ground cinnamon, ground nutmeg, and salt.
5. Combine Mixtures: Gradually add the dry ingredients to the wet mixture, folding gently until just combined. Do not overmix.
6. Add Extras: If desired, fold in the chopped nuts or chocolate chips for added texture and flavor.
7. Fill Muffin Cups: Scoop the batter into the prepared muffin tin, filling each cup about two-thirds full.
8. Bake: Place in the preheated oven and bake for 25-30 minutes, or until a toothpick inserted into the center comes out clean.
9. Cool: Once done, remove the muffin tray from the oven and allow the muffins to cool in the pan for 10 minutes. Then, transfer them to a wire rack to cool completely.

Following these steps will lead you to a batch of amazing Pumpkin-Oatmeal Muffins each time!